Abstract

Excellent ohmic contact formation to undoped-heterostructures is achieved by the incorporation of silicon into metallization.Contact resistance and specific contact resistivity as low as and , respectively, have been obtained for the scheme. Transmission electron microscopy has revealed that the ohmic contact formation mechanism depends on the competing interfacial nitride and silicide formation reactions, the latter giving rise to improved contact performance. The formation and penetration of non-nitride reaction products of Si-containing Al–Au intermetallics to depths beyond the interface were observed. The superior ohmic performance of these schemes suggests that silicide-based low Schottky barrier contact formation may be preferable to an interfacial nitride contact mechanism in achieving improved ohmic behavior.

Received 05 August 2005Accepted 25 October 2005Published online 23 December 2005

Acknowledgments:

This work was supported by ONR under Contract No. N00014-01-1-1000-1072 (Monitor: Dr. H. Dietrich). (S)TEM measurements were carried out in the Center for Microanalysis of Materials, University of Illinois, which is partially supported by the U.S. Department of Energy under Grant No. DEFG02-91-ER45439.